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IBM System z10

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Features

Processors

The number of "characterizable" (or configurable) processing units (PUs) is indicated in the hardware model designation (e.g., the E26 has 26 characterizable PUs). Depending on the capacity model, a PU can be characterized as a Central Processor (CP), Integrated Facility for Linux (IFL) processor, z Application Assist Processor (zAAP), z10 Integrated Information Processor (zIIP), or Internal Coupling Facility (ICF) processor. (The specialty processors are all identical and IBM locks out certain functions based on what the processor is characterized as.) It is also possible to configure additional System Assist Processors, but most customers find the mandatory minimum SAP allocation sufficient.

There are more physical PUs in a machine than characterizable PUs. For example, the E12 has 17 PUs, of which only 12 are characterizable. The remainder is a mixture of spares and mandatory minimum SAPs. The SAPs provide I/O assistance, system accounting, and other critical system functions.

Operating systems

The System z10 supports the following IBM operating systems: z/OS, z/VSE, z/VM, and z/TPF (and its immediate predecessor, TPF/ESA). Other operating systems available include Linux on System z, OpenSolaris for System z, UTS, and MUSIC/SP (at least in principle). A product in development by Mantissa Corporation, z/VOS, was announced in 2008 to run other operating systems developed for x86 architectures (such as Windows and x86 versions of Linux), later renamed to z86VM and the Linux support is in beta, and "has no plans to support 64 bit", but as of 2019, it has a bug for Windows so not even a beta version for it is available.

New features

In addition to much higher performance, System z10 introduced a number of new mainframe features. Some of the more notable enhancements include:

Cryptography

The System z10 adds hardware-based 192-bit and 256-bit Advanced Encryption Standard (AES) in addition to the 128-bit AES support already available on the z9.

Decimal floating point

The System z9 was the first commercial server to add IEEE 754 decimal floating point instructions, although these instructions were implemented in microcode with some hardware assists. The System z10 implements the main IEEE 754 decimal floating point operations in a built-in, integral component of each processor core and instruction set architecture. As examples, Enterprise PL/I, XL C, and the z/OS Java BigDecimal class can exploit hardware decimal floating point.

New instructions

The System z10 processor adds numerous new instructions, primarily concentrated on improving the efficiency and performance of compiled code. The z/OS Java SDK exploits these additional instructions when running on a z10. On July 7, 2009, IBM disclosed z/VM Version 6.1, a new version which requires the additional instructions only available in the System z10 and future models.

z/VM LPAR support

On the System z10, and with the appropriate version of z/VM, a single logical partition (LPAR) can now span all processor types. Previously, IFLs (Linux processors) had to reside in their own separate LPAR(s). This capability improves operational efficiency and simplifies configuration. The z10 also supports much faster z/VM startup from DVD-RAM. Consequently, IBM started providing a no-charge, downloadable z/VM Evaluation Edition.

Capacity on Demand enhancements

System z10 has a simplified, more automated architecture for activation and deactivation of Capacity on Demand processing. In particular, the machine no longer requires immediate, direct contact with IBM for activation of CoD features. IBM also introduced a new Capacity for Planned Events (CPE) offering, which allows mainframe owners to activate CPU capacity temporarily to facilitate moving machines between data centers, upgrades, and other routine management tasks at a much lower cost.

InfiniBand coupling

System z10 provides InfiniBand coupling options for Parallel Sysplex. Some of these options are available for retrofit to the System z9.

HiperDispatch

As the number of cores in the System z machines has grown, IBM engineers have continued to find ways to reduce symmetric multiprocessing (SMP) effects. Adding more cores has diminishing returns in performance due to cache, memory, and I/O contention. The latest effort to reduce these penalties is HiperDispatch, a set of intelligent, cooperative dispatching strategies between the System z10 hardware and z/OS, particularly the z/OS Workload Manager and dispatcher. HiperDispatch steers more processing tasks toward the cores that are "closest" to the cached data the tasks will likely require, minimizing contention for memory and I/O. HiperDispatch helps maintain near-linear SMP scalability and is more relevant to the larger models, but it is enabled by default on all System z10 machines.

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